碼分多址基礎 的英文怎麼說
中文拼音 [mǎfēnduōzhǐjīchǔ]
碼分多址基礎
英文
basics of code division multiple access-
In this paper, after introduction of the code division multiple access ( cdma ) and orthogonal multicarrier ( mc ) technique, the system model of mc - cdma is analyzed and the bit error rate ( ber ) performance in downlink and uplink channel is shown in awgn channel by computer simulation
本文在碼分多址技術和正交多載波技術原理基礎上，分析了高斯白噪聲通道中多載波碼分多址（ mc - cdma ）系統的數學模型，並且使用不同的擴展碼對下行通道和上行通道誤碼率性能分別作了計算機模擬分析。Traditional multiuser detector make good use of all signals which resuilt in multiple access interference so that it provides optimum mai resistance. ( 1 ) nevertheless, it assumes that the receiver can acquire the signature waveform and timing of desired user and the interfering users ; ( 2 ) it has no ability to suppress intercell multiple access interference ; ( 3 ) it cannot be applied in downlink channels. adaptive multiuser detector eliminates the need to know the signature waveforms and the timing of the interferes and has to need training data sequences for every active user
傳統多用戶檢測在單用戶檢測技術基礎上，充分利用造成多址干擾的所有用戶的信息進行聯合檢測，從而具有良好的抗多址干擾能力，但存在一些缺陷： （ 1 ）不僅要求知道期望用戶的地址pn碼及其定時信息，還要求其他干擾用戶的地址pn碼及其定時信息； （ 2 ）不能消除其他相鄰小區的多址干擾對本小區的影響； （ 3 ）不能直接應用在cdma移動通信系統中的下行鏈路。Then we introduce pulse position modulation ( ppm ) using pn code and analysis its multi - access performance, system capacity and power spectrum density. on the basis of those analyses, we study the pulse shape and the anti - jamming ability of the system. at last, multiple access with pseudochaotic time hopping is introduce
本文首先闡述了uwb脈沖通信系統的基本原理，重點介紹了用偽隨機碼跳時的ppm （脈沖位置調制）調制，分析了他的多址性能、系統容量和功率譜密度，在此基礎上研究了改進性能的發射信號形狀和系統抗干擾能力，最後介紹了偽混沌碼跳時的多址方式。Contributions in this paper mainly sh ow four points : 1 the structure characteristic of the received ds - cdma signal is analyzed in the presence of multi - path slow fading effect case for wireless mobile communication. according to this characteristic, four data - selected schemes based on chip - matched filter are presented from the perspective of energy and structure of signal. and the impact of these schemes on multiple - access interference ( mai ) and inter - symbol interference ( isi ) is analyzed
本文的主要貢獻在於四個方面： 1 、針對無線移動通信系統中廣泛存在多徑慢衰落效應的情況，分析了ds - cdma系統中接收信號本身的結構特徵，根據這個特徵，在匹配濾波的基礎上，從能量與信號結構的角度提出了四種不同的數據採用方案，並分析了不同數據方案對多址干擾與碼間干擾的影響。In order to combine the virtues of reservation anoha and cdma, we bring forward the spread aloha ( sana ) protocol and reservation code multiple - access ( rcma ) protocol and analysis their performance
為了結合aloha和cdma的優點，在aloha和prma的基礎上提出了擴展aloha （ sama ）和預約碼多址接入rcma ，並對其性能進行了分析。Assigning serial different address code to different subscribers, useful signal is taken out of the same time slot and frequence, and is transmitted with one share channel. at received end, system makes use of completed address code from sending end to do correlative check and take out useful subscriber signal. the other address code signals are treated as broadband disturbing signal which is removed. in radio environment of existing variable disturbtion and muti - way declining, expand frequence signal ’ s broadband characteristics can improve system performance obviously. cdma mobile telecommunication system has some better characteristics, such as anti - disturbing 、 anti - way declining 、 secrecy 、 capacity 、 utilizing rate of frequence resource and so on, than other mobile telecommunication system
Cdma （ codedivisionmultipleaccess ）移動通信系統的技術基礎是基於擴頻技術的碼分多址，通過給不同的用戶分配各自特定的地址碼序列，將處于相同時隙和頻率的用戶信號分離開來，採用共享通道方式傳輸信息。在接收端，系統利用與發送端完全一致的本地地址碼對接收信號進行相關檢測，提取需要的用戶信號，而將其他使用不同碼型的信號視為寬帶干擾而從中剔除掉。Then, memory cell array and some parts of peripheral circuits used in sram, for example, sense amplifyier and adderss decoder, are designed and verifyied by simulation. furthermore, some novel methods, such as clocked hierarchical word decoding structure, multi - stage sense amplifyier, common data line and data bus equlibruim technology has been applied in the design of 128kbit and imbit sram. what ' s more, we have studied compiler technology applied in the designing course of a imbit full cmos sram from the pointview of methology
然後對sram的存儲單元電路以及外圍電路中的靈敏放大器和地址譯碼器進行了設計和模擬，在此基礎上，以128kb和1mb全cmossram設計為例，從方法學角度對同步sram設計中的帶時鐘分等級字線譯碼，多級靈敏放大和位線及總線平衡等技術進行了研究，並給出了相應的compiler演算法。So the chaotic sequence can indeed serve as spreading address code in spreading communication. after discussing the communication theory of cdma, we propose the model of the ( cd ) 2ma communication system and utilize the simulation tools of matlab simulink to propose the ( cd ) 2ma simulation system according to this model
在論述了碼分多址通信原理的基礎上，給出了混沌數字碼分多址（ （ cd ） ~ 2ma ）通信系統的模型，並依據此模型使用matlabsimulink模擬工具給出了混沌數字碼分多址通信系統的可視化模擬系統。分享友人